959
FXUS65 KBYZ 102355
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
555 PM MDT SAT OCT 10 2026
KEY MESSAGES
- ADDITIONAL COLD FRONT MOVES THROUGH THIS EVENING AND OVERNIGHT
WITH A FINAL PUSH SUNDAY NIGHT. MANY LOCATIONS COULD SEE THEIR
FIRST FREEZE OF THE SEASON SUNDAY OR MONDAY MORNINGS.
- STRONG WEATHER SYSTEM MOVES INTO REGION THIS WEEKEND. SNOW
ACCUMULATION IS LIKELY THIS EVENING THROUGH MONDAY MORNING FOR
SOUTH-CENTRAL MT MOUNTAINS AND FOOTHILLS, WITH RAIN AND WET
SNOW AT LOWER ELEVATIONS.
- WEATHER PATTERN REMAINS UNSETTLED THROUGH MID WEEK, WITH
CONDITIONS GRADUALLY WARMING AND DRYING THROUGH LATE WEEK.
UPDATE
SCATTERED SHOWERS EXIST OVER THE REGION (A LIGHTNING STRIKE WAS
RECENTLY OBSERVED NEAR DERBY MTN) BUT AN AXIS OF STRATIFORM PRECIP
EXISTS OVER THE FAR WEST, FROM ENNIS TO LEWISTOWN, ALONG THE MID
LEVEL BAROCLINIC ZONE. COLD ADVECTION IS UNDERWAY AND JUDITH GAP
IS DOWN TO 32F AT 530PM, AND THE DOT STATION IS REPORTING A CHANGE
OVER TO WET SNOW. A BIT NORTH AT EDDIE'S CORNER, WEB CAMERA SHOWS
HEAVY SNOW OCCURRING. EXPECT PRECIP OVER THE WEST TO INCREASE IN
COVERAGE AND CHANGE TO MOSTLY WET SNOW THROUGH THE COURSE OF THE
EVENING. THIS IS THE START OF THE EVENT AND THE FORECAST IS IN
GOOD SHAPE. JKL
DISCUSSION
TODAY THROUGH FRIDAY...
A LOW PRESSURE SYSTEM IS EXPECTED TO SLIDE THROUGH WESTERN MT AND
TRACK SOUTH AND EAST THROUGH THE WEEK. TROPICAL MOISTURE BEING
PULLED UP FROM HURRICANE RACHEL IS EXPECTED TO BOOST ATMOSPHERIC
MOISTURE VALUES TO 150-250% OF NORMAL, GIVING WAY TO HIGH
CONFIDENCE FOR APPRECIABLE PRECIPITATION ACROSS MUCH OF THE
REGION, ESPECIALLY SOUTH-CENTRAL MT. A FRONTAL PASSAGE ASSOCIATED
WITH THIS SYSTEM IS SET TO MOVE THROUGH THIS EVENING AND INTO THE
OVERNIGHT HOURS BRINGING COOL AND WET CONDITIONS. HIGH CONFIDENCE
EXISTS FOR LOCATIONS OF YELLOWSTONE COUNTY WEST TO RECEIVE AN
INCH OF LIQUID PRECIPITATION WITH THIS EVENT. THE EASTWARD EXTENT
OF THE COOL AIR IS EXPECTED TO GET INTO BILLINGS AND SURROUNDING
AREAS SUNDAY EVENING INTO MONDAY MORNING, LEAVING THAT TIME TO BE
THE BEST TIME FOR RAIN/SNOW MIX. CHANGES TO THE FORECAST/PRODUCTS
INCLUDE AN UPGRADE TO WINTER STORM WARNING STARTING AT 6PM MDT
THIS EVENING DUE TO INCREASED CONCERN FOR HIGHER SNOW AMOUNTS
(NEAR ONE FOOT IN HIGHER TERRAIN) AND BLOWING SNOW IN THE JUDITH
GAP AREA FROM GUSTY NORTH WINDS. ADDITIONALLY, GOLDEN VALLEY,
MUSSELSHELL AND NORTHERN STILLWATER COUNTIES WERE ADDED AS
WINTER WEATHER ADVISORIES SUNDAY EVENING THROUGH MONDAY MORNING
FOR UP TO 4 INCHES OF SNOW. USE CAUTION IF TRAVELING ALONG I-90
AND US-191 THROUGH MONDAY AND CHECK ROAD AND WEATHER CONDITIONS
BEFORE TRAVELING.
HIGHER HEIGHTS BEGIN TO MOVE IN TUESDAY, BUT AS THE LOW MOVES
THROUGH WY, LOW TO MODERATE PRECIPITATION CHANCES REMAIN IN THE
FORECAST FOR LOCATIONS ALONG THE MT/WY BORDER. ALTHOUGH THE UPPER
LEVEL PATTERN DIFFERS AMONGST ENSEMBLES IN THE LONG TERM, BOTH
PATTERNS INDICATE WARMER AND DRY CONDITIONS FOR THE END OF THE
WEEK.
HIGH TEMPERATURES WILL RANGE FROM THE 30S TO LOW 50S SUNDAY AND
MONDAY, WITH MANY LOCATIONS SEEING THEIR FIRST FREEZE OF THE YEAR
SUNDAY AND MONDAY MORNINGS. TEMPERATURES WILL BEGIN TO REBOUND
INTO THE 40S AND 50S TUESDAY AND WEDNESDAY, INCREASING INTO THE
60S BY THE END OF THE WEEK. TS
AVIATION
A COLD FRONT WILL DROP THROUGH THE AREA FROM NORTH TO SOUTH THIS
EVENING. EXPECT INCREASED SHOWER ACTIVITY ALONG THE FRONT AS IT
MOVES THROUGH, AND AN ISOLATED THUNDERSTORM CAN'T BE RULED OUT.
PRECIPITATION BECOMES MORE WIDESPREAD OVER THE WESTERN FOOTHILLS
THIS EVENING WITH GUSTY EASTERLY WINDS. LOCALLY HEAVY SHOWERS
COULD PRODUCE IFR CONDITIONS. AFTER 06Z, EXPECT PRECIPITATION TO
BECOME A PERSISTENT RAIN OVER THE WESTERN HALF OF THE FORECAST
AREA (KBIL/KSHR/KLVM) RESULTING IN PREDOMINANTLY MVFR TO IFR
CONDITIONS OVERNIGHT. SNOW LEVELS DROP UNDER 6KFT AGL FOR THE
WESTERN MOUNTAINS AND FOOTHILLS BY SUNRISE SUNDAY MORNING. PERIODS
OF RAIN/SNOW WILL MOVE OVER THE AREA FOR SUNDAY. MOUNTAINS WILL
BE OBSCURED AT TIMES THROUGH THE PERIOD. STP
PRELIMINARY POINT TEMP/POPS
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 038/042 032/042 031/051 035/057 040/060 037/060 041/070
++/R +8/O 11/B 11/B 21/B 10/U 00/U
LVM 031/038 026/043 025/053 027/057 030/060 029/064 034/072
++/O +6/O 01/B 01/U 12/W 10/U 00/U
HDN 039/047 033/045 030/054 034/059 036/061 032/062 032/072
9+/R +8/R 11/B 12/W 21/B 11/U 00/U
MLS 041/048 035/044 035/052 036/057 040/059 035/057 037/068
69/R 99/R 11/B 12/W 21/B 11/U 00/U
4BQ 043/051 040/048 037/054 039/058 041/059 037/058 039/070
37/R 86/R 12/R 23/W 32/W 11/U 10/U
BHK 035/050 030/046 031/054 033/059 035/060 031/058 032/068
58/R 98/R 11/B 12/W 32/W 21/B 00/U
SHR 040/049 033/047 030/054 033/057 035/059 031/061 033/072
57/R 94/R 23/R 44/W 44/W 21/U 00/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM SUNDAY TO NOON
MDT MONDAY FOR ZONES 29-34-42.
WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
NOON MDT MONDAY FOR ZONES 40-65-66-141-228.
WINTER STORM WARNING IN EFFECT UNTIL NOON MDT MONDAY FOR
ZONES 63-67-68.
WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO NOON
MDT MONDAY FOR ZONE 172.
WY...NONE.
WEATHER.GOV/BILLINGS
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